Page:Muscles and Regions of the Neck.djvu/18

16 goitres by the knife have been almost superseded by the discovery, that iodine exerts a marked controul over many enlargements of the thyroid body; and it would evince other boldness than that of knowledge, lightly to undertake the excision of a tumour so importantly connected. The jugular vein, the carotid artery, the pneumogastric nerve, which on each side the diseased body would overlap,—the trachea and œsophagus, which it would almost encircle, might indeed be avoided in an attempt at its removal; but the enormous venous as well as arterial hæmorrhage that must occur, and the extreme likelihood of dividing the recurrent nerves, would involve a not small possibility of accelerating the fatal result, and deter every prudent surgeon from attempting an operation of such extraordinary risk, except under circumstances that might justify the most favourable remote prognosis. The ligature of its nutrient arteries has been advocated as a cure for bronchocele; but, although this mode of procedure presents fewer anatomical difficulties than that last mentioned, yet, from surgical considerations of its extreme uncertainty and unsafe protraction, it seems little entitled to preference.

On the left side, the œsophagus, inclining from the median line, presents itself in the antero-inferior triangle. It only half emerges from behind the trachea (which still covers its right portion), and closely lies on the vertebræ: it continues the canal of the pharynx, from a line of abrupt distinction opposite the lower edge of the cricoid cartilage, downward. It is at its commencement that this tube most frequently interests the surgeon, by becoming the seat of stricture, or by arresting and fixing foreign bodies. To this space the operation of œsophagotomy belongs; and the left side is, for obvious reasons of convenience, chosen for its performance. In Mr. Arnott’s instructive paper on the subject the following directions occur, which may serve to illustrate the anatomy of the region in regard of the operation in question: “The situation of the external incision will, in some measure, depend upon that of the body to be removed, but as the pharynx, tapering gradually in its descent, terminates in the œsophagus immediately under the larynx, it is here that a bulky substance is most apt to be detained. In reaching the œsophagus at this place, taking as a centre a spot corresponding to the level of the lower margin of the cricoid cartilage and the first ring of the trachea, the only parts of consequence, whose injury is to be dreaded, are the inferior thyroideal artery and recurrent nerve, (the superior thyroideal artery being too high to run any risk;) but these will not be wounded, if the same plan is adopted as that in the case related, of separating the deeper-seated parts by the handle of the scalpel and the finger instead of by the knife. Here they were not seen during the operation, in fact they were not within the sphere of the wound, for, on examining the parts after death, the artery and nerve were found below and on the inner side of it. Still I am satisfied by trials on the dead body, that the artery is likely to be divided if the operation is completed by the knife, and hence the expediency of proceeding deliberately, cutting but little at a time, sponging carefully, so as to see and avoid the artery, if possible, or to tie it immediately when cut. The recurrent nerve runs less risk as it reaches the side of the trachea, to which it is attached in its ascent, lower down. I do not allude to the carotid artery as being exposed to any peril. I think, with Mr. Allan Burns, that he must be wanton indeed in the use of his knife, who hurts this vessel. In making the incision into the œsophagus, it is to be remembered that the recurrent nerve runs in the angle between this tube and the trachea, and therefore the incision is to be made a little behind this angle.”

3. Antero-siperior triangle.—This pretty nearly corresponds to the depression which in lean subjects is seen at the side of the neck beneath the jaw and in front of the sterno-cleido-mastoid muscle. It is bounded behind by the diagonal line to which we have so often referred; the posterior belly of the digastric and the superior belly of the omo-hyoid constitute, respectively, its upper and lower borders, and their convergence to the hyoid bone anteriorly forms its apex. The fascia superficialis, enclosing the platysma myoides, extends uninterruptedly over its borders; and the cervical aponeurosis splitting at each, extends singly over the area which they enclose: the transverse processes of the vertebræ, covered by muscular attachment and by the pre-vertebral aponeurosis, form its floor. The common carotid artery enters it below, and, at about the level of the lower border of the third vertebra, divides into the internal carotid, which continues to the cranium the direction of the trunk, and the external, which runs and ramifies in more superficial parts; the sympathetic, as in other regions of the neck, lies between the posterior layer of the sheath of the vessels and the pre-vertebral fascia; the superior laryngeal nerve lies in the same interval, obliquely bending from above to the posterior part of the thyro-hyoid membrane behind the vessels: it is on the confines of this triangle and the digastric space that the posterior belly of that muscle, accompanied by the stylo-hyoid muscle above and the lingual nerve below, arches across the external and internal carotids, and at about this level the stylo-glossus and stylo-pharyngeus with the glosso-pharyngeal nerve intervene between those large arteries. It is only below this crossing that the vessels fall under our present consideration, and their study may he facilitated by extending an arbitrary line of division from the os hyoides (at the apex of the space) transversely backward. Such a line would have below it the trunk, bifurcation and continuing branches of the common carotid, and the origin from the external of the superior thyroid artery alone; while, above the level referred to, the continued secondary trunks would be seen, and many of the branches